Sem a lista, eu sempre esqueço o leite e o pão.

Sem means without and it takes a noun phrase directly: sem + noun.
So sem a lista = without the list.

• da = de + a (of/from the), which doesn’t fit after sem here.
• com means with, the opposite idea.

Lista is a feminine noun in Portuguese, so it uses feminine articles and adjectives:

• a lista = the list
• uma lista = a list

There’s no rule that all nouns ending in -a are feminine, but lista is.

The comma separates an introductory phrase (Sem a lista) from the main clause. It’s very common in Portuguese (and also fine in English):

• Sem a lista, eu sempre esqueço... = Without the list, I always forget...

You might see it without a comma in informal writing, but the comma is standard and clear.

Eu is optional because the verb ending -o in esqueço already tells you it’s I. Both are possible:

• Sem a lista, eu sempre esqueço... (more explicit; often used for emphasis or clarity)
• Sem a lista, sempre esqueço... (more natural/colloquial in many contexts)

In Portuguese, adverbs like sempre commonly go before the main verb:

• eu sempre esqueço = I always forget

You can move it for emphasis, but the most neutral placement is exactly as in the sentence.

Esqueço is present tense, 1st person singular (I forget). It comes from the verb esquecer.

Present tense (eu):

• eu esqueço = I forget / I do forget / I’m prone to forgetting (depending on context)

In Portuguese, esquecer can be used in two common patterns:

1) esquecer + direct object (very common)

• esqueço o leite e o pão = I forget the milk and the bread

2) esquecer de + infinitive / clause / sometimes a noun

• esqueci de comprar leite = I forgot to buy milk
• esqueci do leite (common too) = I forgot about the milk

In your sentence, the direct-object version is straightforward and natural.

Portuguese often uses definite articles where English might not, especially with everyday items in context.

• o leite = the milk
• o pão = the bread

You can drop them in some contexts (especially lists, labels, or very general statements), but here o leite e o pão sounds natural as “the milk and the bread (I was supposed to buy/remember).”

Portuguese often repeats the article with each noun in a coordinated pair, especially in careful or neutral speech:

• o leite e o pão (very common)

You might hear o leite e pão in faster/informal speech, but repeating o is standard and clear.

Yes, there’s a nuance:

• Sem a lista = without the (specific) list (the one you normally use)
• Sem lista = without a list / without any list (more general)

Both can work, but sem a lista strongly suggests a known, specific list.

Pão is roughly like powng (one syllable, nasalized), not like pah-oh.

The ã indicates a nasal vowel. In Brazilian Portuguese:

• pão sounds nasal and ends with a nasal quality, often written in pronunciation guides as /pɐ̃w̃/ or similar.

Yes, that’s grammatically fine. It changes the rhythm and emphasis:

• Sem a lista, eu sempre esqueço o leite e o pão. (focuses first on the condition: without the list)
• Eu sempre esqueço o leite e o pão sem a lista. (states the habit first, then adds the condition)

The original version is especially natural when setting up the context first.